Sheathed flexible shafting



March 18, 1941. v c WUESTNER 2,235,189

SHEATHED FLEXIBLE SHAF'TING Filed May 17, 1939 71:15. T513 31 I; 2 36 "I; f

INVENTOR C- J. LO

ATTORNEYS.

Patented Mar. 18, 1941 PATENT OFFICE snsn'rnsn FLEXIBLE SHAFTING Clarence, J. Wuestner, Ardsley, N. Y., assignor to United Hoisting 00., Inc., New York, N. Y., a -corporationof New York Application May 17, 1939, Serial N0. 274,137

3 Claims.

This invention relates to sheathed flexible shafting of the kind adapted to extend between, and to transmit rotary power drive between, a driving element or motor and a freely manipulable element or tool, wherein the interior flexible shaft portion rotates within the non-rotary flexible sheath, the sheath and the shaft both extending between end bearings arranged respectively at the driving or power-end and the driven or tool end of the combination. The reference to a tool at the driven end is intended to include any instrument or device driven through the flexible shafting. A typical instance is a vibrator, spud or spade adapted to be forced into freshly laid concrete, yet unset, and there vibrated to drive air out or otherwise to improve the setting action or quality of the concrete. The invention however may be used for rotary tools such as drills and various other devices desir'ed'to be operated by power while being yet free to be manipulated and applied to the work in any convenient manner or direction.

The general object of the present invention is to afford a sheathed flexible shafting of the kind referred to, formed with sections or couplings, andwhich will have improved efficiency and convenience in action. A particular object is to afford such a sectional constructionof shaft'ing, that may be built up to various lengths desired, the interior or rotary shaft portion of which is sectional and is adapted to be freely self-adjusting in length to accommodate itself 3 to the changes in relative length of the sheath portion which inevitably occur in practical use. An espe cial object is to afford a construction wherein the rotary sectional shaft portion is provided with couplings between its sections, eachcoupling pair comprising male and female members having rotary driving engagement and endwise sliding adjustment of one relatively to the other without being subject to accidental uncoupling during use.

Other and further objects and advantageswill be explained in the hereinafter following description of an illustrative embodiment of the invention or will be understood to those conversant with the subject. To the attainment of-such objects and advantagesthe present invention con sists in the novel sheathed flexible shafting and the novel features of combination, construction and arrangement herein illustrated or described.

In the accompanying drawing Fig. 1 is a perspectiveview of a complete equipment f-rom the driving end, including motor,- to the driven-end,

including a typical tool at the end of a considerable length of the shafting.

Fig. 2 is a central cross section of a typical portion of the construction, for example adjacent to the tool at the driven end of the shafting.

Fig. 3, partly in side view and partly in central section, shows a short length of the interior flexible shaft portion, consisting of the adjoining parts of two sections and the coupling pair for coupling them, being shown uncoupled, but the coupled position indicated in dotted lines.

Fig. 4 is a partial view similar to Fig. 3 but showing the mode, characteristic of this invention, of coupling or uncoupling the male and female members of the pair.

Fig. '5 is a right end elevation of the female coupling member shown in Figs. 3 and 4.

' Fig. 6 is a left end elevation of the male coupling member.

'Fig. 7 is a sectional View of the male member taken on the line of Fig. 3.

The driving member of the entire combina tion may be considered as the rotary shaft l0, appearing in Fig. 1, this being power driven from an electric or other motor ll through convenient gearing l2. At the other end the tool or device M, which is freely manipulable, is shown as comprising a rotary or driven member l5 which in this case is enclosed within a shell I 6, in the nature of anon-rotary hollow frame. The shell 30 I6 is formed with a bearing piece or head I! and this may contain a ball or other bearing l8 be tween the shell and the tool shaft 25 to bede scribed.

Referring further to the non-rotary elements, the tool shell I6 is provided with a sleeve or extension within which, in a usual manner, may be tightly secured the flexible sheath 2|. This sheath may be composed mainly of rubber or other flexible material which is adapted to retain lubricant, and it may be surrounded by a metallic armor or strip 22. Tracing the sheath member back to the power end, the flexible portion 28 may be firmly connected with a fixed sleeve member 23, adjacent to the motor H, and this sleeve may enclose and constitute the bearing for the driving member or rigid shaft 10.

The rotary part l5 of the tool is shown as connected with a rigid tool shaft turning within the non-rotary parts I1 and 18. Between the tool shaft 25 and the driving shaft l0 extends the interior flexible shaft 21, with couplings between it and the rigid shafts l0 and 25. The flexible shaft may be substantially conventional and is shown of the built-up type composed for 55 connected by two rigid sleeves or joints 29 Preferably the interior rotary shaft has a disengageable coupling at each of these sectional di-v visions so that, m the illustrated case, there will be a total of four coupling pairs in the rotary shaft, one each near the driving and driven ends and one near each division sleeve between sec-;

tions.

At each coupling point of the rotary shaft there is a female coupling member 3| in engagement with a male coupling member33, these being adapted to communicate torsion or rotation while being freely relatively slidable. It is already known to provide a male coupling member of semi-cylindrical form slidable within a cylindrical female member having, at a point well inwards of the end thereof, a crosspin preventing rotation of the male member and thereby affording communication of rotary drive. Such an arrangement however has, proved defective in practical use. For several reasons the, male member was liable to slide far enough to disengage the cross pin of the female membenthus to destroy operative coupling engagement between the members. The sliding action is essential for several reasons. Thus the sheath has a tendency to stretch or lengthen while the shaft or cable has a tendency to shorten,,so that while the sheath may have a predetermined initial length the shaft must be self adjustable to accommodate itself to changes. The shaft rotates loosely within the sheathing with substantial clearance, so that a relative longitudinal movement may occur by the mere bending of the entire shafting. When there are several sections of the interior shaft, the intermediate ones may all slide toward one end, for example toward the tool, so that the aggregate movements may readily be sufiicient todestroy the coupling engagement at one point at least. Further, the sheath may become detached or loosened at one of its joints, tending to lengthen it or allow the shaft to come apart. On any such accidental-disengagement of the coupling member considerable trouble is caused in recoupling them. The present invention operates to avoid these difiiculties and yet in a manner to permit ready coupling of the male and female members in the processof assembly, or uncoupling them at will.

The female member 3| is shown as a hollow cylindrical sleeve mounted on one of the rigid end shafts or on the flexible shaft or cable. Thus, as shown in Fig. 3, the shaft 2'! is shown jammed into one end of the member 3| as a socket, where it may be soldered, pinned, or welded in place. At the coupling end the member 3| is provided with an end closure 32 shown in the form of a segmental wall, for example slightly lessthan semi-circular. This wall is located at or very close to the entrance to the member, and partly closes the entrance. The closure 32 may be integral with the cylindrical wall of the member 3|, or may be, as at 32 in Fig. 2, attached or welded in place. The provision of the entrance closure 32 leaves an opening or unclosed space 33, preferably slightly greater than a semi-circle. In the form shown in Fig. 2 the female member is connected, not to the cable shaft 21, but to the rigid shaft 25, the member therefore having a stem 34 threaded or attached to the end of the shaft 25.

With this characteristic female member cooperates the male coupling member 36 having the particular construction shown. Its shank portion 31 is hollow, forming a socket for the cable shaft 21, although if this member is to be attached to a rigid shaft it may have a stem 34 siniila'r't'o that shown in Fig. 2. The male coupling member comprises also a part-cylinder or semi c'ylindrical extension or slide 38, adapted to be acc'ommodated'within the female memb'ef 3 .;In"cross, section the slide portion 38 of the male member may be complementary to the end closure 32 of the female member; in other words it may fit operatively within the unclosed space 33 ofthe latter. As thus far described the male member might become accidentally disengaged by sliding away from the female member, but this is prevented by the provision, at the extremity of the slide 38, of an end lug 39, of the general character of a hook, standing outwardly preferably at right angles to the slide, and being substantially co-extensive with the area of the end closure 32 of the female member. It may frequently be advisable or necessary to round off the corner of the slide 38 opposite to the lug 39; the drawing shows theslide so shaped or truncated at {8. Or the sleeve'3l could instead be cut away opposite the wall 32 to accommodate the corner of the slide'38.

By reason of thedescribed structure, the female member having its segmental closure at its entrance, andthe male member having a lug or hook at its extremity, it is possible to engage and disengage the members in the manner illustrated in Fig. 4, but this can only be done by intention, and not accidentally. This is done by relatively tilting or swinging the two members to a substantial angle, such as the angle 42, which is substantially greater than any angle that may be produced by the bending of the shafting. When so relatively tilted the malemember slide and 1118 38, 39, slip readily into and out of disengagement with the female member 3| and its end closure wall 32, being facilitated by the truncated or rounded shape 48 of the slide 38. When once engaged the couplingpair affords eificient rotary driving engagement and at the same time permits adequate sliding self-adjustment, lengthwise of' the shafting, within the sheath, the closure 32 and the lug 39 however acting as mutual stops preventing endwise disengagement or uncoupling within the sheath.

A practl6al application may comprise the use of seven foot'l'ong flexible sections, using one, two or more thereof, transmitting driving torque for example at 4000 R. P. M. The interior rotary element may be considered as comprising the two rigid end-sections or rotors l8 and 25 and one or more intermediate flexible sections rotating within the flexible sheath. The exterior element asinternal spiral llningaifording a well-known type.

of bearingsurface for the loosely contained flexible drive shaft, with plumbago or other lubricant between. Other practical uses are for grinding tools, pumps, compressors, speed indicators and motion picture projectors.

There has thus been described a sheathed flexible shafting embodying the principles and attaining the objects of the present invention. Since many matters of arrangement, construction and design may be variously modified without departing from the principles of the invention, it is not intended to limit the invention thereto except so far as set forth in the appended claims.

What is claimed is:

l. A sheathed flexible shafting of the kind adapted to transmit rotary drive between its driving and driven ends and wherein its interior shaft rotates within its non-rotary sheath, and characterized as follows: the interior shaft comprises flexible shaft sections with coupling pairs between sections for continuous connection and rotary drive, the female member of each pair comprising a rotary sleeve having a thin stop wall partially closing its entrance but leaving an offset entrance space, the male member comprising an elongated slide having a non-circular section adapted to occupy operatively said space and having a thin stop lug extended laterally from its end into alinement with said stop wall, whereby the coupling pair while having rotary driving engagement is slidably self-adjustable lengthwise within the sheath, and whereby said stop wall and lug act as mutual stops preventing endwise uncoupling within the sheath, and whereby the coupling members of each pair when the shaft is removed from the sheath may at will be coupled or uncoupled by a relative swinging thereof to a substantial angle permitting the thin lug end to be tilted through the unclosed entrance space of the sleeve of the female member.

2. A sheathed flexible shafting of the kind adapted to transmit rotary drive between its driving and driven ends and wherein its interior shaft rotates within its non-rotary sheath, and characterized as follows: the interior shaft comprises flexible shaft sections with coupling pairs between sections for continuous connection and rotary drive, the female member of each pair comprising a rotary sleeve having a thin stop wall partially closing its entrance but leaving an offset entrance space, the male member comprising an elongated slide having a non-circular section adapted to occupy operatively said space and having a thin stop lug extended laterally from its end into alinement with said stop wall.

3. In or for a sheated flexible shafting, a flexible interior shaft rotatable within a flexible sheath and comprising shaft sections carrying at their adjoining ends male and female coupling members, the male member having a shank of non-circular section longitudinally slidable to a substantial extent within the female member, the female member having at its entrance a short closure wall leaving a non-circular space accommodating said shank in such manner that the two members are compelled to rotate together, and said shank having a short ofiset head at its end cooperating with said closure wall to limit endwise movement and prevent uncoupling of the members inside the sheath but permitting swinging and uncoupling when out of the sheath.

CLARENCE J. WUESTNER. 

